Regional Civil Defence group controller Neville Reilly said those who do need to travel should take extreme care on the roads and reduce speeds to suit the hazardous conditions.

The deluge which has hit Christchurch since Saturday afternoon is far more than the city typically gets for the whole month of June.

The MetService says more than 90 millimetres has fallen at Christchurch airport since Saturday afternoon. The city typically has 60mm of rain for the whole of June, though the wettest June on record in 1995 was 183mm.

Four schools have closed, a welfare centre has been set up, and some Banks Peninsula towns are being urged to conserve drinking water.

Wet roads may have contributed to the death of an 18-year-old whose vehicle was found in a flooded ditch near Tai Tapu.

The body of Oliver Steven Mills, of Tai Tapu, was found in his vehicle about 10.30am on Sunday.

Authorities have also named the woman who died after a landslide engulfed her home at Sandy Bay, north of Motueka on Sunday. She was Jude Hivon, 63, described by her neighbour Tim Wraight as "a great little soul".

Civil Defence has set up a welfare centre at Mairehau Primary School, in one of the worst-affected parts of the city.

Meanwhile, the Christchurch City Council is transporting fresh water to Akaroa, Takamatua and Duvauchelle, in Banks Peninsula, where residents are being urged to conserve water.

City water and waste contracts manager Tim Joyce said Banks Peninsula drinking water was running low after heavy rainfall saw "unclean stormwater to mix with clean stream water".

Christ the King School in Greers Rd, Burnside, failed to open this morning because of "severe flooding" while Rangiora High School sent pupils home at 11am due to fears over closed, or flooded waters in the district.

Ashley School and Sefton School, also in North Canterbury, have now closed.

Motorists across Christchurch and Canterbury are being urged to take care with concealed potholes a risk for cyclists, pedestrians and drivers.

Surface flooding has been reported in St Albans, Beckenham, New Brighton, Northwood, Burnside and Sumner. One northbound lane on the Fitzgerald Ave bridge, north of Kilmore St, is closed due to floodwaters.

The roads have proved a challenge for city ambulances though St John said it had see very few injuries specifically related to the weather.

MAIREHAU SHOPS UNDER WATER

Butchers at Peter Timbs Meats have set up a pallet walkway from the middle of Edgeware Rd to the shop front, so customers can reach the door.

Heavy rain overnight had caused the street outside his house to flood to knee-level, ruining his car and his two flatmates' cars.

"The first thing I thought was, 'Is it only here or is it this bad everywhere else?'. Then I thought, 'holy s... my car. It's written-off'."

He and his flatmates planned to stay home today because of the flooding in Thornton St, which had surrounded their house.

Strong, who worked for a computer store, only had third-party insurance on his car and would have to rely on the city buses to get to work in the central city.

"I haven't got a car now," he said.

A Canterbury Earthquake Recovery Authority (Cera) spokesman said the agency was not dealing with any urgent weather-related issues, but was monitoring the situation.

"We have since Friday been actively monitoring properties in the Port Hills that could potentially pose a risk in these conditions."

The MetService website appears to have crashed under heavy demand this morning.

The traffic lights at the intersection of Bealey Ave and Barbadoes St were out of action this morning, meaning drivers were required to use the give way rules when passing through.

A Christchurch City Council spokeswoman said the lights were back on by 8.30am.

Meanwhile, a possible line fault cut power to 434 homes in Avonside, North Linwood and Richmond for 41 minutes at 12.45am today.

HAY BALES FOR NORTH CANTERBURY HOME

A North Canterbury family desperately stacked hay bales around their home to divert floodwaters, but could not stop the flow from rushing through their house for the second time in less than a year.

Repairs to Karl Horwarth's Mairaki Rd property had just been completed when last night's heavy rain flooded it for the second time since August last year.

The two-storey house had needed to have new carpets, paint and joinery installed and Howarth expected the same would be needed this time.

"We're miles away from the race, but it comes all the way down our driveway, 800 metres, takes a nice left-hand turn and comes into our house."

The flooding was worse this year, but the family had been expecting it.

"Last time we woke up to it ... and we were sloshing. This time we were able to get up and get most stuff out of it in time."

Horwarth's brother-in-law, Andrew Thomas, had been out at 1am using hay bales in an attempt to divert the water from the house.

The Fire Service and Waimakariri District Council had also been out to help, but the water had managed to sneak passed, flooding the family's garage and entering their house.

Howarth's elderly parents also lived on the property following Canterbury's earthquakes and had been forced to leave because of the flooding today.

His father, who had dementia, had been put into emergency respite care, but Howarth, his partner and 8-year-old son hoped to be able to stay in a granny flat behind the main house that had not been affected by the flooding yet.

"We had talked to the Waimakariri council. We've been on them constantly since it happened last year ... but nothing's happened."

The garden surrounding the house had also been trashed by the flooding and would be covered in mud and silt when the water subsided.

"It's like liquefaction really."

Waimakariri District Council emergency management advisor Brennan Wiremu said a house in Aldersgate Rd, Kaiapoi, had also been flooded this morning.

Water was also threatening two properties in Kairaki Beach and one in King St in Rangiora.

Members of Civil Defence's volunteer rescue team were at the affected homes to help divert water and give support.

"Anybody who thinks their life is at risk or thinks the water is going to rush through their house should call 111 in the first instance ... then call the council," Wiremu said.

The MetService expects heavy falls to clear North Canterbury this afternoon.

PLANE STRUCK BY LIGHTNING

Flights in and out of Christchurch and Dunedin do not appear to be delayed by the weather, but 160 passengers flying from Christchurch to Auckland were given a fright when their plane was struck by lightning.

Christchurch East MP Lianne Dalziel was on the Air New Zealand flight when she heard a ''bang and a flash''.

The plane was travelling through cloud when the lightning struck and the pilot spoke to passengers a few minutes later to let them know what had happened.

Dalziel said she had never been in a plane when it was hit by lightning before and was surprised by the noise it made.

''It wasn't terribly loud, although it woke up my fellow passenger. In all the time I've been flying it hadn't happened before I'm glad that's all it was.''

An Air New Zealand spokeswoman confirmed flight 504 from Christchurch to Auckland was hit by lightning on its approach to Auckland this morning.

There had been 163 passengers on board.

The aircraft would now be inspected by engineers before being cleared to return to service, the spokeswoman said.